This looks like a type of wasp, though we cannot ID it to species as we can't see enough detail. (Plus, one of the wasp families we suspect it belongs to, Ichneumonidae, contains hundreds of species found in Maryland, several of which will have only subtle differences.)

We can determine it's not a social wasp (that is, one that forms communal nests like a hornet or yellowjacket) and many of the solitary wasps are specialists on only certain kinds of insect prey. They don't bother people and would be highly unlikely to sting, if they can sting at all. This one looks like a female since it seems to have an ovipositor at the end of its abdomen. (This is the blade- or straw-like structure that lays eggs; it also serves as the stinger for species that can sting.) Many wasps with notably long ovipositors use them to parasitize larvae of wood-boring insects deep inside tree or shrub branches or under bark. This is considered a benefit to gardeners as it protects trees from the wood damage borers can cause. Some wasps even parasitize other wasps already using the larva as their own food source - an amazingly complex "circle of life," so to speak.

Miri